import 'package:english_words/english_words.dart';
import 'package:flutter/material.dart';
import 'package:flutter_app/material/egMaterialApp.dart';

void main() => runApp(new MaterialAppDemo());
//void main() => runApp(new LongListView(items: new List<String>.generate(500, (i) => "Item $i")));

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Startup Name Generator',
      home: new RandomWords(),
      theme: new ThemeData(primaryColor: Colors.white),
    );
  }
}

class RandomWords extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return new RandomWordState();
  }
}

class RandomWordState extends State<RandomWords> {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Startup Name Generator'),
        actions: <Widget>[new IconButton(icon: new Icon(Icons.list), onPressed: _pushSaved)],
      ),
      body: _buildSuggestions(),
    );
  }

  void _pushSaved() {
    Navigator.of(context).push(new MaterialPageRoute(builder: (context) {
      final tiles = _saved.map((pair) {
        return new ListTile(
          title: new Text(
            pair.asPascalCase,
            style: _biggerFont,
          ),
        );
      });
      final divided = ListTile.divideTiles(tiles: tiles, context: context).toList();

      return new Scaffold(
        appBar: new AppBar(
          title: new Text('Saved Suggestions'),
        ),
        body: new ListView(
          children: divided,
        ),
      );
    }));
  }

  final _suggestions = <WordPair>[];
  final _biggerFont = const TextStyle(fontSize: 18.0);
  final _saved = new Set<WordPair>();

  Widget _buildSuggestions() {
    return new ListView.builder(itemBuilder: (context, i) {
      if (i.isOdd) return new Divider(); //添加分割线

      final index = i ~/ 2; //除以二并向下取整
      if (index >= _suggestions.length) {
        _suggestions.addAll(generateWordPairs().take(10)); //再生成十个单词，添加到列表中
      }

      return _buildRow(_suggestions[index]);
    });
  }

  Widget _buildRow(WordPair pair) {
    final alreadySaved = _saved.contains(pair);

    return new ListTile(
      title: new Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      trailing: new Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      onTap: () {
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }
}
